Three-way hydraulic cylinder for hydraulic brakes



Aug. 5, 1952 P B BURHANS 2,605,864-

THREE-WAY HYDRAULIC CYLINDER FOR HYDRAULIC BRAKES Filed Oct. 18, 1950Patented Aug. 5, i952 THREE-WAY HYDRAULIC CYLINDER FoR- 1 .HYDRAULICBRAKES.

Paul B. Burhans, Miami, E19,,- M I pplication October 18, 1950, Serialnoyisoan This invention relates to brake construction wherein brakeshoes are expanded into contact with a brake drum, by hydraulic means,to brake the wheel of which the brake drum forms a part.

The primary object of the invention is to provide means whereby thebrake shoes will be uniformly expanded or forced against the brake'drum, insuring an effective braking of the wheel, and at the same timepreventing uneven wear of the brake lining, due to the brake operatingpressure being applied at one point.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention consists of certain novel details ofconstruction and combinations of parts hereinafter more fully describedand pointed out in the claim, it being understood that changes may bemade in the construction and arrangement of parts without departing fromthe spirit of the invention as claimed.

Referring to the drawing Figure 1 is a sectional view through a brakedrum and brake, illustrating an operating means constructed inaccordance with the invention.

Fig. 2 is a fragmental sectional view through a brake drum illustratinga modified form of the invention.

Referring to the drawing in detail, the referiolaim. (c1. 188--152) ingpivotal connection withthe links that extend in opposite directions andconnect with the bearing members 2 I that ares'ecured to the shoes 6, atpoints adjacent to the lower ends thereof. Upper coiled springs 22connect with the upper portions of the shoes 6 at the outer ends of thesprings, the inner ends of the springs being connected to the ring I6,at a point adjacent to the piston rod I5. I

At the lower portion of the ring I6, springs 23 are provided, thesprings 23 stretching across the drum, where they are connected to theears 24 that'extend inwardly from the brake shoes 6. Thus it will beseen that due to this construction, the springs 22 and 23 normallyoperate to draw the brake shoes inwardly.

The reference character 25 indicates an opening in the wall at thecylinder 8, into which brake fluid is forced in the usual and well knownmanner, by the operation of the master cylinder of a hydraulic brakesystem, not shown.

' The outer ends of the cylinders are closed by I means of the rubberdiscs 25 to exclude foreign ence character 5 indicates a brake drum, andthe I reference character 6 indicates brake shoes which are suppliedwith the usual brake lining I that cooperates with the brake drum inbraking the wheel, of which the brake drum forms a part.

The invention embodies a three-way hydraulic cylinder indicatedgenerally by the reference character 8, which cylinder comprises thehorizontal section 9 and the vertical section Ill, the horizontalsection 9 communicating with the vertical section III, through theopening II disposed at a point intermediate the ends of the section 9.As shown, the section I9 is substantially larger in diameter than thehorizontal section, and is provided with a piston I2 that operatestherein.

Pistons I3 are mounted in the horizontal section 9, the rods I4 of thepistons I3 being riveted to the brake shoes 6 at opposite sides of thebrake drum 5, adjacent to the upper ends of the brake shoes, as shown byFig, 1 of the drawing.

The piston rod I5 on which the piston I2 is mounted, connects with thering I6, the ring I6 encircling the axle H on which the wheel, not shownis mounted.

Extending from the ring I6 is the ear l8 to which the arm I9 isconnected, the arm I9 havmatter which would impair the eflicientoperation of the pistons.

In theform of the invention as shown by Fig. 2 of the drawing, the brakedrum is indicated by the reference character 21, and the separable brakeshoes operating therein, are indicated by the reference character 28.

Bearings 29 are secured to the lower ends of the brake shoes 28 andsupport the grooved rollers 39 throughwhich the wedge-shaped member 3Imoves to expand the lower ends of the brake shoes in the same manner asthe mechanism shown at I9 and 20 of Fig. 1 of the drawing.

The coiled springs 32 connect with the shank of the member 3| and havetheir outer ends connected to the shoes at 33, to normally draw thelower ends of, the brake shoes inwardly.

It will be understood that the ring 34 of which the member 3| forms apart, is moved vertically by a structure identical with the structureshown in Fig. 1 of the drawing, and which includes the horizontalcylinder 9 and vertical cylinder Ill, together with the pistons whichmove therein.

In the operation of the device, it is obvious that when braking fluid isforced into the threeway cylinder, by the usual master piston of ahydraulic braking system, the pistons will be moved in oppositedirections, to expand the brake shoes evenly throughout their lengths,thereby distributing wear on the'brake bands or lining of the brakes toreduce wear at a particular point, which is the result of app y thebrakes or brake shoes at the upper ends thereof, as is customary in theconventional type of hydraulic brake shoe operating mechanism.

Having thus described the invention, what is claimed is:

In a fluid brake, an axle, a fixed support, a 1'0- tatable drumsurrounding the fixed support and axle, a pair of brake shoes mounted onthe fixed support cooperating with said rotatable drum in brakingmovement of the rotatable drum, .a

three-way hydraulic cylinder including pistons mounted on the fixedsupport, comprising communicating horizontal cylinders and a verticalcylinder disposed at right angles with respect to the horizontalcylinder, communicating with the horizontal cylinder, said verticalcylinder being of a diameter appreciably greater than the diameters ofthe horizontal cylinders, pistons operating in the cylinders, a bearingring surrounding the axle in spaced relation therewith,

bearing members mounted .on the lower ends of the brake shoes, a pistonrod-connected between 4 the piston operating in the vertical cylinderand said ring, links connected between said ring and said bearingmembers spreading the lower ends of the brake shoes against therotatable drum as the piston in the vertical cylinder moves downwardly,means for connecting the pistons operating in the horizontal cylindersto the upper ends ofthe shoesand said cylindershaving an opening throughwhich ifluid is directed 370* the cylinders operating said pistonssimultaneously.

PAUL B. BURI-IANS.

' REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS "Pointer Mar. 21, 1950

